Barcelona has bucked the almost irresistible trend to let an external agency design a ‘smart city,’ and instead has done it itself. The result is an open source software suite called Sentillo and already it has been adopted by two other Spanish cities. The design relies almost entirely on the range of Waspmote sensors from Spain’s Libelium and if lots of other cities follow the Barcelona lead, this should mean a dramatic uptick in sales for the company. Libelium has recently unveiled a raft of new products including upgrades to its most famous product, the Waspmote sensor, which is essentially a micro controller and an antenna that users can attach any of 70 sensors to. Sentilo claims to be the…